Mineral oil compositions



3,201,351 MINERAL OIL COMPQSITIGNS Joseph E. Fields and John H. Johnson, Dayton, Ghio, assignors to Monsanto Company, a corporation of Delaware No Drawing. Filed June 12, 1961, Ser. No. 116,247 8 Claims. (Cl. 252-56) mixtures of these additives steadily increase in viscosity and may eventually gel. A new type of Viscosity index improver and/or pour point depressant which is an isobutylene/fumarate polymer has been discovered and very v surprisingly this new additive is quite stable and compatible with the barium detergent additives in mineral oils.

It is an object of this invention to provide new and improved viscosity index improvers which are stable in mineral oils in the presence of barium or otherbasic detergent additives, p a

It is another object of this invention to provide new and improved pour point depressants which are stable in mineral oil in the presence of barium or other basic detergent additives. e I

It is another object of this invention to provide new and improved viscosity index improvers and pour point depressants which are stable in mineral oil in the presence of barium or other basic detergent additives.

These and other objects of the invention will become apparent as the detailed description of the invention proceeds. e

The compositions of the invention have mineral oils as the major component, i.e. in excess of 50% by weight of the compositions, and'minor amounts atleast sufficient to increase the viscosity index substantially and/ or to lower substantially the pour point of the base oil of oil-soluble polymers of isobutylene and alkylfumarates. Other monomers in minor amounts can also be polymerized with the isobutylene and fumarates to form useful compositions. Also other oil additives can be'present in the mineral oil, especially "barium detergent additives, if

desired. The isobutylene/fumarate polymers are present in the composition of-the invention in concentrations ranging from about 0.05% th 5% or more, preferably from 'of isobutylene will be used in the process. point depressant use a'mixture of straight-chain alcohols .ranging fromabout 8 to about 24 carbon atoms prefer- Patented Aug. 1 7,' 1 985 motor oil for automobiles. For good viscosity index improving properties normally it will be preferred to use a polymer having an average molecular weight within the range of about 15,000 to about 100,000 preferably 20,000

' to about 70,000; however, higher and'lower molecular weight polymers will be operable. For pour point depressant uses it is preferred that the molecular weight of the polymer be below about 10,000, polymers having molecular Weights of 2,000'to 3,000 being quite satisfactory, although 15,000 to 20,000 or higher molecular weight polymerswill be eflective as pour point depres sants. The useful polymers of the invention must of course be soluble in the mineral oil in amounts and over the temperature range at Which the mineral oil composition is to be used and normally preferred polymers will be soluble in mineral oil, e.g. an SAE- 20 grade mineral lubricating oil to the extent of at least about 1% by weight at room temperature. To insure that the polymers will be soluble in mineral oil, the average number of carbon atoms in the alkyl groups of the fumarate should be at least about 6.5 preferably in excess of about 7.0. These polymers of fumarate and'isobutylene are substantially 1:1 molar isobutylene to fumarates regardless of the ratio of the monomers charged in the processof producing the polymers, and normally a molar excess For pour ablyfrom about' lO to 18 carbon atoms should be used to esterify fumaric acid making the fumarate monomers. For the purpose of this application lower alkyl is defined as 1 to 6 carbon atoms and higher alkyl as 8 to 24 carbon atoms.

An illustrative listing of suitable furnarates to choose from as comonomers with isobutylene is set forth below as follows: dimethyl fumarate, diethyl fumarate, methyl ethyl fumarate, diisopropyl fumarate, di-t-butyl fumarate, methyl n-butyl fumarate, di-n-butyl fumarate, di-isobutyl fumarate, di-n-amyl fumarate, di-n-hexyl fumarate, di-nheptyl fumarate, di-n-octyl fumarate, di-Z-ethyl-hexyl fumarate, di-isooctyl fumarate, di-n-de'cyl'fumarate, dioxodecyl fumarate, butyl n-decyl fumarate, di-n-dodecyl fumarate, -di-t-dodecy1 fumarate, di-oxotridecyl fumarate, di-L-orol fumarate, di-tallow fumarate, di-n-eicosyl fumarate, etc. Tallow fumarates are obtained by esteri, fying fumaric acid with a mixture of about 67% by weight of C and 33% by weight of C straight-chain alkyl alcohol. Di-Lorol fumarates are obtained by esterifying fumaric acid with a mixture of 3%C 6 l%C 23%- C ll%-C and 2%,-C straight-chain alkylalcohols.

An illustrative list of third-types of monomers which can be polymerized with isobutylene and fumarates to form polymers which have special properties such as low ,temperature detergency or other properties in addition to high'viscosity index and low pour point are the following: styrene, both higher and lower alkyl methacrylates such as methyl methacrylate, vinyl acetate, isopr-openyl acetate, vinyloxye thanol, vinyl ethyl ether, B-hydroxyethyl 'butyl fumarate, B-hydroxyethyl Adol 14 fumarate, dl", methylaminoethyl 'butyl fumarate, diethylaminoethyl Adol 14 fumarate, and the like.

The invention will be more clearly understood from the following detailed description of specific examples thereof.

EXAMPLE 1 This example describes the preparation of an isobutylene/dibutyl fumarate copolymer.

Into a Coke bottle were placed 74 grams of water, 22.8 g. of dibutyl fumarate, 33.6 g. of isobutylene, 0.213 g. of potassium persulfate, and 1.14 g. of Aerosol OT, 21 commercial wet ting agent.

The bottle was flushed with nitrogen, capped fied by dissolving in benzene and precipitating from methanol. 'Yield of purified polymer was 75.4% (21.4

g.). An elemental analy yielded the following results:

sis of the purified product Found Theoretical 0, percent..... 67. 4 67.6 H, percent----. 10.1

A number of other experiments were carried out wherein isobutylene was copolymerized with various fumarates and mixtures of fumarates. The data from these experiments is summarized in Table I below.

Table 1 Run No 1 Run No.2 Run No. 5

MonomerslB/BF. IB/2EHF IB/EF/oDF. IB/fumarate mole charge ratio- :1 6:1 0 4:1. Product composition, mole ratio 1:1 10: Fumarates, average N 0. alkyl carbon atoms- 6.0 6.0. Mole Percent Catalyst KgSgOg-AOT- 0.8% B220 Pressure, p s i Q Autogenous. Temperature, C 70 75. Time, hours. 24 24. Yield, percent 71.7 87.5.

Percent polymer in cone. of Base Oil 1 Oil vise. in Base CH2, 3% polymerKinematic visc csl:

.At 100 F 147.2- At 210 F 16.19 Specific viscosities:

.At 100 F 0.008- At 210 F 0.509- Efficiency- 0.936- V 1186.-.- 109.4" 116.9. Remarks Emulsion Emulsion Emulsion hexane 20% hexane polymer. polymer polymer. solvent. solvent-haze.

Run No. 6 Run No. 7 Run No. 8 Run No. 9 Run No. 10 Run No. 11

Monomers IB/EF/oDF--- IB/EF/oDF---- IB/EF/oDF-.-. IBIEF/ QDFUU IB/EF/oDE---- IB/EF/nDF. IB/fumarate mole charge ratio 12:1 12:1. 12:1 12:1 12:1 12:1. Product composition, mole ratio 10:5:5 10:3:7 10:4:6 10:0:4 10:5:5 10:525. Furtnarates, average No. allryl carbon 6.0- 7.6-. 6.8- 5.2- 6.0- 6.0.

a oms. Mole percent catalyst 0.8% B2202 0.8% 131202 0.8% B7402 0.8% B71202 0.8% B2202 0.8% 137, 0 Pressure. p.s.i.g Autogenous. Autogenous..-.. Autogenous--.-. Autogenous. 3500-HO 4000-11 0. Temperature, C 82 70 70 70.- 70. Time, hours 24 24... 24 24. 18 18. Yield, perccnt.. 92.5- 97.8. 94.3. 92.5- 96.1c 98.40. Percent polym. in cone. of Base Oil 1-. 30..-..- 40 40 30. 40. Oil vise. in Base Oil 2, 3% polymer- Kinematie Viscosity, cs.:

Y 98.5. 133.14. 125.17 13.06 96.78 111.15 At; 210 F 12.06- 14.68- 14.08. 4.18- 13." .40. Specific viscosities:

At100 0.075. 0.454- 0.365-... 2.659. 0.056. 0.212. At 210 F. 0.163- 0.422- 0.356. 2.040. 0.324. 0.298. Eiliciency- 2.173- 0.930- 0.981. 0.767-. 5.786. 1.377. V. 117.6- 114.9- 115.3. 2165-. 132.5 119.6. Remarks- Haze Oil nonioam- 7.5% polymer Haze insol. oil Haze ing. in Base Oil 3. non foaming.

Run No. 12 Run No. 13 Run No. 14 Run No. 15 Run No. 16 Run No. 17

Monomers IB/nDF IB/EF/nDF IB/EF/nDF IB/nDF IB/EF/11DF IB/EF/nDF. IB/fumaratc mole charge ratio 12:1 12:1. 12:1 12:1 12:1. 12:1. Product composition, mole ratio 1:1 10:4:6 10:5:5 1:1 10:4:6. 10:5:5. Fninarates, average No. alkyl carbon 10.0..- 6.8--- 6.0..- 10.0... 6.8.. 6.0.

a ems. Mole percent catalyst 0.8% B2 0 0.8% B2 02 0.8% B140 0.8% DCBZ O H 0.8% DCBZgOz-. 0.8% DCBZzOz. Pressure p.s.i.g Autogenous Autogenous..--- Autogenous.-- Autogenous Autogenous---. Autogcnous. Temp., 70.-- 70 50 50 50. Time, hours. 24 24 24 40 10 40. Yield, percent. 93.0.-. 96.4-- 95.8.. 100 90.4. Percent polymer in cone. of Base Oil 1-. 40 40.-. 40 40 40 40. Oil vise. in Base Oil 2, 3% polymer Kinematic viseosities, cs.:

At 100 F 125.76 116. 111.56. At 210 F. 13.99. 13.23- 13.28-. Specific viscoslties:

100 0.373.-. 0.276-. 0.218.. At 210 F- 0.356. 0.275- 0.297 Efllerency 0.954... 0.900.- 1.317... V. 114.2--. 113.7-.. 118.3..- Remarks Oil non-foam- Oil non-foe mg. jug-haze. 111g. temp.

Table IContinued Run No. 18 Run No. 19 Run No. 20 Run No. 21 Run No. 22 Run No. 23

Monomers IB/EnDF IB/AuF IB/EF/A14F IB/EF/AuF 1B/EF/A14F IBIEAMF. IB/iumarate mole charge ratio. 12:1 12:1 4:1 4:1 4:1 12:1. Product composition, mole ratio 1: 1: 10:5: 10:5. 5:4.5..-- 10:6:4 1:1. Fumarates, average N 0. alkyl carbon 6.0-.. 13.0-. 7.5-.. 6. 6.4.-- 7.5.

atoms. Mole percent catalyst- 8% DCBZQOZ 0.8% DOBZZOQ-.. 0.2% DOBZgOg 0.4% DOBZQOB... 0.4% DCBZ O H 0.8% DCBZgOg. Pressure, p.s.i.g Autogenous. Autogen0us. 25,000-IB Autogenous---.- Autogenous- Autogenous. Temperature, 0 50 50 o 50 50. Time, hours. 24 24 17 48 48 24. Yield, percent- 100! 1000 93.60- 1000 100 1000. Percent polymer in cone. of Base Oil 1-. 40 4o 40 40 4o 40.

Oil vise. in Base Oil 2, 3% polymer- Kinematic viscosities, cs.:

Efficiency C .I----. .9.-- 115. Remarks Oil non-foam- Oil uon-foam- Insoluble haze--. Non-foaming mg. ing. oil.

Run No. 24 Run No. 25 Run N0. 26 Run No. 27 Run No. 28 Run No. as

Monomers IB/EF/EAHF.-- IB/BF/A14F IB/BF/A14F- IBAEg/BF/ IBIQIEFIEI H IB/BA F.

14 IB/iumarate mole charge ratio 4: 4:1 4:1 4:1 4:1 M 4:1. Product composition, mole ratio :2:8 10:5:5 10:6.5:3.5.-- 10:6:1:3.- 10:2:2:6 1:1. Furtnarates, average No. alkyl carbon 6.4-.- 8.5-.- 7.15--. 5.5-.- 5.7-.. '8.5.

a oms. Mole percent catalyst 0.4% DQ131102 0.4% DQ132202 0.2% DCBz O u 0.4% DUE 0 0.4% DQ132 0 0.4% DCBZQOQ. Pressure, p.s.i.g Autogenous. Autogen0uS.-- 25,000-IB Autogenous. Autogenous.-- Autogenous. Temperature, C 50 50 50 50 50 50. Time, hours. 24 9 24 24 24. Yield, percent. 100 100 95.10. 100c 1000 1000 Percent polymer in come. of Base Oil 1-. 4c 40 40 40 30.

Oil visc. in Base Oil 2, 3% polymer- Kinematic viscosities, cs.:

At 210 F Specific viscosities 0.891--- 0.062 0.483. 9 0.929--- 0.467 0.484. 1.043... 7.532 1.002. 123. 118.3--- 125.3--- 139.5 118.4. "Remarlm Insoluble, not Insoluble haze...

run.

Run No. 30 Run No. 31 Run No. 32 Run No. 33 Run No. 34 Run No. 35

Monomers I /B l4 1B/BF/BAHF--- IB/BF/BAuF--- IB/BF/BA14F- IB/EF/BAmF--- IB/BF/A F. IB/fumarate mole charge ratio 4:1 4: 4:1 4:1 4:1 4: 1. Product composition, mole rat 10:4:6 10:5:5 10:6;4 10:2. 75:7 25-. 10:6:4. Fuinarates, average No. alkyl carbon 6.7-.. 6.25.. 5.8 6.7 7.6.

a oms. Mole percent catalyst 0.4% DOBZZOB... 0.4% DGBZ O M 0.4% DQ132 0 0.4% DQ132 0 0.4% DQ132 0 Pressure, p.s.i.g Autogenous. Autogenons-- Autogenous Autogenous Autogenous. Temperature, O 50 50 50 50. Time, hours.... 24 24 24 24 24 24 Yield, percent" 1000 1000 1000 1000 1000. Percent polymer in cone. of Base Oil 1-- 30 30 30 40 28.6 40. Oil visc. in Base Oil 2, 3% polymer- Kinematic viscosities, cs.:

At 100 F 133.57 131.89.- 130.53.. 110.22.. 127.61 140.07 At 210 F-- Specific viscosities: 100 At 210 F Efficiency V.I. Remarks Polymer system: LEGEND IB-Isobutylene Run No. 30 Run No. 37

EFDiethy1 fumarate 'l Monomers IB/BF/Ar4F IB/BF/AuF. 60 L Dlbutyl fumame llpB/imiarate mole; charge fancies..." 152 2 2bHF2-ethylhexyl fuinarate ro uct composi ion mo e ra i0... 1 I i Fumarates, average 100. alkyl car- ODF l Oxocecyl fdmarate bon atoms 67.7.3) CB 0 3.2 7 DCB O nDFDi-n-decyl furnarate Mole percent catalyst 0.4 1.2 2" z: z. A. Pressure p.s.i Autogenousflu- Autogenous. AMP 1 j (fumamte prepmed, 3 Temperature, 0 50-.. 50. r estenfymg Iurnanc acid with a mixture of straight l 24 chain alcohols of the following composition: Yield, percent 1000 1000. Percent polyin. in conc.ofBase Oil 40 40 3%-C 65.7%C 20.2%C 1O.6%C and 05%-c Oil V150. 1n Base 011 2, 37 poly- 13 megn T 0 EnDFEthy1-n-decyl furnarate 1I1m3 0 156051 CS.:

At F 135151 10542 70 14 y Ado} 14 fdmarate S 1521c" F 15.57 15.12. BA FButyl Adol 14 fumarate eci c viscosi ies: D At 100 F 0.479 0.151. SMStYrene At 210 F 3-079 IPAc-Isopropenyl acetate 912 119.333: 114.4: Y acetate Renwrk Ha e 7 VOEfi-Hydroxyethyl vmyl ether or vmyloxyethanol VEE-Vinylethy1 ether LEGENDCntinued Catalyst:

K S O AOT-Potassium persulfate-Aerosol OT Bz O Benzoyl peroxide DCBz O Dichlorobenzoyl peroxide Pressure A-Autogenous (isobutylene) 4000 H O--4000 p.s.i. maintained with water 4000 IB4000 p.s.i. maintained with isobutylene Yield: Those marked c determined by materials balance from oil concentrate preparation. All others determined by polymer precipitation from alcohol Base Oil No. 1:

This is a solvent refined Mid-Continent petroleum lubricating oil having the following properties:

Base Oil No. 2:

This oil is a solvent refined Mid-Continent petroleum lubricating oil having the following properties:

Viscosity at 210 F., cs. 10.39 Viscosity at 100 F., cs 91.73 Viscosity index 103.4

Flash point, Cleveland open cup, F 450 Base Oil No. 3:

This is a mineral hydraulic designed to meet Government specification of MIL-0-5606 as follows:

Specific gravity, 60/60 F 0.862

Remarks: Haze-Borderline solubility at room temperature.

The legend set forth above after Table 1 is applicable to Table 1 and the other tables which will be set forth below.

EXAMPLE 4 This is a detailed description of Example 4 which is summarized in Table 1 above. The reactor was a small steel bomb, which was flushed with nitrogen and chilled in an ice bath. To this steel bomb were charged 52.6 g. of di-oxodecyl fumarate, 44.6 g. of isobutylene, 20 ml. hexane and 0.6 g. of benzoyl peroxide. The bomb was then capped and tumbled in an air oven at 75 C. for 24 hours. Then the bomb was rechilled in Dry Ice, opened and any excess isobutylene allowed to evaporate upon Warming to room temperature. The hexane was removed and the polymer purified by dissolving in benzene and precipitating from ethyl alcohol. Pressure during the run was autogenous pressure generated by isobutylene at the temperature of reaction. Yield of polymer product was 93.3%. A sample of the polymer product Was dissolved in Base Oil No. 1 to make a 30% concentrate. This 30% concentrate was diluted to 3% polymer with Base Oil No. 2 for viscosity measurements. The results of the viscosity measurements are reported in Table 1.

EXAMPLE This is a detailed description of Example 10 summarized in Table 1. The reactor used in this experiment was a magnetically stirred reactor called a Magne-Dash reactor designed for high pressure operation. To the Magne-Dash reactor were added 118.6 g. of isobutylene, 34.9 g. of di-oxodecyl fumarate, 15.2 g. of ethyl fumarate and 0.6 g. of benzoyl peroxide. The reactor was then flushed with nitrogen and pressured up with water to 3500 p.s.i.g. Reaction period at 70 C. was 24 hours. The 3500 p.s.i.g. was not maintained since the run continued over night and the next morning the pressure was 300 p.s.i.g. in the bomb. The polymer was dissolved in 117.5

. g. of Base Oil No. 1 and 400 ml. of benzene.

The water and benzene were removed under water pump vacuum 0 .to a pot temperature of 180 C. Yield of polymer was 57.6 g; (96.1% yield). An additional 16.9 g. of process oil was added to make the 30% concentrate. A sample of the polymer concentrate was diluted to 3% polymer with Base Oil No. 2 for viscosity measurements. The resulting oil was hazy indicating insolubility of the polymet and the oil was non-foaming. In this experiment a little too much ethyl fumarate was used as indicated by the insolubility, the average number of alkyl carbon atoms being 6.0. V

EXAMPLE 20 This experiment was carried out in a high pressure rocking type bomb. To the bomb were charged 71.25 g. of di-Adol 14 fumarate, 23.84 g. of diethyl fumarate, 62.1 g. of isobutylene and 0.82 g. of 2,4-dichloro benzoyl 'peroxide catalyst. This catalyst contained 50% of the active ingredient, the peroxide. The bomb was then pressured up to 25,000 p.s.i.g. with isobutylene and maintained at 50 C. for 13 hours. For the last 4 hours of reaction time giving a total time of 17 hours the reaction mixture was maintained at 60 C. To the polymer product was added Base Oil No. 1 to make a concentrate of the polymer. Excess isobutylene was then stripped 01f the polymer concentrate and an additional 15 g. of the oil added to readjust to 40% polymer concentrate. Yield was 93.6% polymer.

EXAMPLE 29 The procedure and equipment used in this example was the same as was used in Example 4. To the small bomb was charged 31.5 g. of isobutylene, 52.1 g. of butyl Adol 14 fumarate and 0.9 g. of 2,4-dichloro benzoyl peroxide active). Pressure in the run was autogenous established by the presence of excess isobutylene. Reaction temperature was 50 C. and polymerization run time was 24 hours. At the end of the polymerization run Base Oil No. 1 was added to the polymer to make a 30% concentrate and the usual stripping and readjusting of the base oil was carried out to establish the 30% polymer concentrate in Base Oil No. 1. As usual a sample of the 30% concentrate was diluted with Base Oil No. 2 to 3% polymer for viscosity measurements.

EXAMPLE 41 This example describes the preparation of an isobutylene fumarate polymer containing a third monomer. The experiment was carried out in equipment and in a manner similar to that described in Example 4. To the small bomb was charged 17.4 g. of isobutylene, 2.6 g. of isopropenyl acetate, 53.1 g. of di-Adol 14 fumarate and 0.63 g. of 50% active 2,4-dichloro benzoyl peroxide. The pressure was autogenous established by the presence of excess isobutylene, reaction temperature 50 C. and reaction time 5 days. Base Oil No. 1 was added to the polymer product to make up a 40% polymer concentrate and the usual stripping and oil adjusting carried out. Yield was 98.0%. A sample of the polymer concentrate was diluted with Base Oil No. 2 to 3% polymer and viscosity measurements were made.

In Table 2 below are summarized a number of runs wherein isobutylene and fumarates are polymerized with a third monomer. Run 41 of this table is discussed in detail above. In column 3 of this table a 4:1 molar excess of isobutylene is shown and this means a 4:1 excess over the sum of the number of moles of the fumarate plus the third monomer.

Table 2 Run N o. 38 Run No. 39 Run N0. 40 Run N0. 41 Run No. 42 Run N0. 43

Monomers IB/V OE/A14F IB/VE/A14F IB/IPA0/A14F IB/IPAc/A F IB/VEE/Auli.-- IB/VEE/A F. IB/fumarate mole charge ratio 4:1 4:1 4:1 4:1 4:1 4:1. Produst composition, mole ratio 2:2:4 3:1:4 2:2:4... 3:1:4 222:4 3:1:4. Mole percent catalyst 0.4% DCBz Oz" 0.4% DCBZgOz 0.4% DCBz2O 0.4% DCBZgOi 0.4% DOBZgOg... 0.4% DCBZ'zOg. Pressure, p.s.i.g Autogenous Autogenous Autogenous Aut0gen0us Aut0gen0us Autogenous. Temperature, C 50 5 50 5 50 50. Time 5 days 5 days 5 day 5 days 5 days 5 days. Yield, percent 96.30.- 97. 95.5c. 98. 97.50 98.70. Percent polymer in cone. of Base Oil 40 40 40 40 40. Oil visc. in Base Oil 2, 3% polymer- Kinematic Viscosities cs EXAMPLE 45 liquid flows. An empty 600 ml. beaker is placed under This experiment describes the preparation of a polymer having no isobutylene therein. The experiment was carried out in the same type of equipment and in the same manner as Example. 1. charged 24.65 g. :of di-ox-odecyl fumarate, 5.35 g. of vinyl acetate, 10 ml. of hexane and 0.3 g. of benzoyl peroxide catalyst. Reaction temperature was 75 C. and reaction time 24 hours. A 30% concentrate of polymer and oil was made in the usual manner and the volatiles stripped ofl. Yield of polymer was 94.7%. A sample of the 30% concentrate was diluted with Ease Oil No. 2 to 3% polymer and viscosity measurements were made.

In Table 3 below are summarized a number of runs of polymers made containing fumarate monomer plus another monomer but no is-obutylene monomer. Run 45 described in detail above exemplifies these experiments.

To a Coke bottle were the double discharge tube. Oilers are opened on the machine and adjusted to several drops/minute. Then the motor switch is turned on. The motor switch is turned oif when the fluid level reaches the neck of the reservoir. (This will prevent the introduction of air into the feed system.) The reservoir is once again filled with the pre-test flush fluid and the above sequence of steps repeated.

Now the equipment is ready for the regular shear test. A fresh sample of the test fluid is poured into the reservoir (minimum of 150 ml. plus ml. for each inter mediate sample to be taken). The rubber connector hose between the reservoir and the machine i squeezed to expel any-air trapped therein. A clean 600 ml. beaker is placed under the discharge nozzle. Then the motor switch is turned on. The motor switch is turned off when the fluid level reaches the neck of the reservoir.

Table 3 Run. N0 44 Run No. 45 Run N0. 37 Run No. 48

Monomers ODF. ODF/VAG 0D F/EF. oD F/SM. Molar charge ratio. 1: 80:20 wt. 1:1. Solvent Hexane Hexane Hexane Hexane Hexane. Catalyst and weight percent 3 wt. percent 3 wt. percent 3 wt. percent 3 Wt. percent 3 wt. percent B2202. B2203. B2303. B2202. B2202. Temperature, C 75 75 75. Time, hours. 24 24 24 24. 24. Yield, percent 70.0-- 94.7 85.0 68.0.. 83.3. Percent polymer in cone. of Base Oil 1 30 30 30. Oil vise. in Base Oil 2, 3% polymer- Kinematic vlse.. cs:

10 F 117.5 At 210 F 14.08-- Specific visc At 210 F 0.358 Efllciency 1.270 V.I. 120.5 112.7. Remarks 30% 011 mm 30% oil cone.

In Table 4 below the results of shear tests are compared between a polymer of the invention, the product of Example 20, and Acryloid 710 which is a good com- 7 p The beaker of sheared fluid is removed and stirred or mercial viscosity index improver having satisfactory hear.

The shear test is a diesel injector shear test. This test is used to evaluate the viscosity-stability of fluids. This is accomplished by passing the fluids through a diesel injector for a number of cycles. The actual diesel injector test machine used was a General Motors diesel head assembly, 1-71 Series, No. 5154288; with injector No. 5226710; operating at 1800* cycles per minute.

. In a pro-test flush the glass reservoir of the equipment is filled with test fluid to the level of the supporting ring; about 200 ml. of test fluid. The injector bleed valve is opened and the equipment is allowed to drain until a known reference fluid for comparison to the unknown fluids.

After the completion of the shearing run the motor switch is turned on and the system is run dry, then three 100-ml. portions of Stoddard solvent is used to flush out the system.

anhydride copolymer similar to that used for pour dep. A, which polymer was esterified to the extent of about 65% with a mixture of straight-chain alcohols having 3.0%-

Table 4 C10, 65.7%C12, 20.2%-C and 0.5%"C18 alcohols and the balance of the esterification being ac- On viscosities in Base on 2, 3% polymer complished with -dimethyl-1,3-propylenediamine to R give a 65/ 35 ester imide copolyrner. In additlon to pour gf Monomers Kinematic vim 9 1; depressant A, two other pour point depressants were 3 tested for compatibility with the isobutylene/fumarate 35 polymers. The first of these pour point depressants is a Before Shear After Shear commercial additive Acryloid 150 which is a methacrylic ester polymer, and the other of these additives is 20 IB EFA F 19.40 14.73 50.87

l d lm" 19.56 14.12 V 24 grgtrhacommercial pour point depressant called Santo 1 A commercial polymethacrylate Vl improver. It will be seen from an examination of Table 5 that the 7 isobutylene/fumarate polymers are compatible 1n con- It 15 Seen from Table 4 that the Polymer of mven' centrated oil solutions with pour depressant A and the has as se or sqmewhat better shear Propertles than detergent additive but are not compatible with the Acrythe PP{" loid 150 and the Santopour C polymers. In dilute To test tha compatlblhty m cncentmte d sollltlons P solutions (up to 5-7% total additive) all additives were lsobutylene funllarzfte PP of i mventlon compatible with polymers of the invention, however. some other lubricating oil additlves, mixtures of additives In Table 6 below is set f th a comparison f h b Were made and compatibility Observations came? fdrolysis stability of a number of different additives with The results of these compatibility tests are summarized in th isobutylene f t dditi f th invention, I Table 5 below. this hydrolysis method a 2 to 2 /2 weight percent polymer Table 5 IB/tumarate Compatibility ratings No. Pour Low temp.

depressant detergent Run No. Monomers 1 hr. 1 day 5 days 1 week 4 weeks 8 weeks 15 IB/nDF Pour dep.A-. Clear.... Clear Clear Clear Clear 7 Cleai gpm- 15 IB/nDF De rdo do do man man $0. 11 IB/EF/nDF Pour dep.A "do-.." V. sl. haze V. sl. haze V. s1. haze. V. 51. haze V. sl.haze. 11 IB/EF/nDF Deterent rln Clear Clmr Clear Clear Cleaggpmi0 IB/EF/oDF Pour dep. A do (in do (lo do 5 0. 10 IB/EF/oDF Detergent do do dn dn dn Do. 14 IB/EF/nDF Acryloid 150 .Hazy 2-layers- 14 IB/EF/nDF Santopour C. Turbid Turbi 2layers V. sl. means very slight.

In Table 5 the composition of all blends was adjusted to give 15 parts of pou-r point depressant polymer or low temperature detergent polymer to 100 parts of V1. improver (isobutylene/tumarate) polymer giving a total of 115 parts of polymer additives as a concentrate in Base Oil No. 1. Pour Dep. A was an ethylene/maleic anhydride copolymer having a specific viscosity of about 0.1 determined from a 1% solution of the polymer in solution (0.05 mol carboxyl equivalent) was made up in 250 ml. of benzene/isopropanol (1 :1 by volume), and to this solution was added 0.05 m-ol of potassium hydroxide. This mixture was then heated at 70 C. during the duration of the test with samples being withdrawn periodically for determination of potassium hydroxide consumption. Blank experiments were run at the same time as the polymer experiments. These hydrolysis tests dimethyl formamide at 25 C., which polymer was esterare summarized in Table 6 below.

Table 6 Fumarate, Percent hydrolysis after specified time Run Polymer av. N 0. alkyl No. carbon atoms 0.5 hr. 1.0 hr. 4.0 hrs. 8.0 hrs. 24.0 hrs.

90/10 decyl/ethyl polyacrylate 1 80. 0 "Acryloid 710 12 13 15 17 21 EIVLA Lorol ester 72 1 2 5 87 3 100 3 92 SM/oDF (1:1) 17 23 32 40 54 1 Gel.

ified with a mixture of straight-chain alcohols having 2.5% C1Q, 55-5'%C12, 21.0%C14, 10.2%C16 and 10.8%C alcohols therein. The particular detergent additive used in compatibility tests of Table 5 was a deter- Using 2 equivalents of KOH.

5 Using 3 equivalents of K011.

In Table 6 a number of ditferent polymers are compared with polymers of the invention in hydrolysis stability. The Acryloid 710 is a commercial polymethacrylate V.I. improver and the EMA Lorol ester is an gent prepared from a 0.1 specific viscosity ethylene/maleic 75 ester of ethylene/maleic anhydride copolymer wherein 13 v the alcohol used was a mixture of long-chain straightchain alcohols marketed under the trade name Lorol. Other polymers can be identified from the legend set forth after Table 1 or the detailed description in Table 6. It Will be noted that none of the polymers which are not polymers of the invention even compare in hydrolysis stability to the polymers of the invention except the Acryloid 710, which is a good commercial VJ. improver of satisfactory hydrolysis stability. further noted in analyzing the data of the table that optimum hydrolysis stability is attained by certain combinations of isobutylene and certain fumarate mixtures.

The superior hydrolysis stability of polymers of the invention is especially demonstrated in the presence of It will be 1 14 type of V1. improver in Tables 7-13 below. The two commercial V11. improvers are Paratone 430 and 460 which are copolymers of vinyl acetate and fumarates. The comparison is made by incorporating a Paratone or a V1. improver of the invention and one of three difierent barium detergents in Base Oil No. 2 in the normal amounts in which these additives would be added to a mineral lubricating oil in use. The stability of each of these additive blends in mineral oil is checked atfter varying storage periods at room temperature or 60 C. by measuring viscosities at 100 and 210 F. Increasing viscosityprovides indirect. evidence of hydrolysis and the greater the rate and amount ofjv-iscosity increase up to barium detergents and compared with one well known 15 gelation,*the more unstable is theadditive combination.

7 Table 7 PARAIONE 430 PLUS DETERGENTS Specific viscosity Percent specific Percent viscosity increase Paratone 430 Percent 13a detergent Blending 100 F. 210 F. 100 F. 210 F.

Amoco 121: 2% hr.RT 0.085 0. 083 Experimental Bo.

detergent: 2% V2 hr.RT 0.036 0.029 Santolube 333:

2 hr.-RT 3% hr.- 0. 690 0.925 3% 24 hr.60 O 0.681 0.929 3% 72 hr.60 C 0.690 0.929 3% 168 hr.60 G 0. 685 0.915

(0. 775)c (1. 008)c e e 3% 11r.-RT 1. 063 2. 974 37. 2 195.0 3% 1 hr.60 0-- 1.637 2. 814 111. 2 179. 2 3% 24 11r.-G0 O- 3. 104 4.349 300.5 331. 4 3% 72 hr.-60 C--- 4. 005 5. 288 416. 8 424. 6 3% 168 hr.60 C 4. 648 6. 182 499. 7 513. 3

Experimental Ba detergent: (0. 726) c (0. 954) o c e 3% 2% hr.-RT 0. 896 1. 796 23. 4 87.1 3% 1 hr.60 0-- 1. 215 1. 653 67. 4 73. 3 3% 24 ion-60 O- 1. 489 2.007 105.1 110. 4 3% 72 hr.60 O.-- 1. 673 2. 214 130. 4 132.1 3% 168 hr.60 C 1.867 2. 461 157. 2 158.0

3% hr.-RT 1. 049 1. 568 52.0 69. 5 3% 1 hr.60 0-- 1.177 1. 583 70. 6 71.1 3% 24 hr.60 O 1. 372 1. 774 98. 8 91.8 3% 72 hr.60 C--. 1. 552 2.007 124. 9 117.0 3% 168 hr.60 C 1. 749 2. 271 153. 5 145. 5

1 RT means room temperature. c-C orrected tor viscosity contribution oi detergent.

T able 8 PARA'IONE 460 PLUS DETERGENTS v Specific viscosity Percent specific Percent viscosity increase Paratone 460 Percent Ba detergent Blending 100 210 F 100 F. 210 F.

3% hr.R1 1 0.838 1. 281

3% 24 hr.60 C. 0. 829 1. 277

3% 168 hr.60 C 0.817 1. 231

7 (0.923) c (1. 364) c c i c 3% hr.-RT- 1. 273 r 5. 039G 37. 8 209. 4 3% 1 hr .60 C. 2. 158 4.112G 133. 8 201. 5 3% 24 h1.-60 C 3.389 6.871 267. 2 403. 7 3% 72 Luz-60 O 5. 449 '8. 835G 490. 4 547. 7 3% 2% 168 hr.60 C 6. 412 10. 337G 594. 3 657. 8

Experimental Ba detergent: (0. 874)c (1. 310)c o c 3% 2 hr.-RT 1.067 2. 304 22.1 75. 9 3% 1. 377 2. 295 57. 6 75. 2 3% 1.878 r 2. 757 114. 9 110. 5 3% 2.123 3. 061 142. 9 133. 7 3% 2. 301 3. 292 163. 3 151. 3

3% 1. 275 2. 114 52. 1 65.0 3% 1. 498 2.160 78. 8 68. 6 3% 1. 092 2. 330 101. 9 81. 9 3% 72 hr.60 C 1. 881 2. 556 124. 5 99. 5 3% 16 h1.-60 C 2. 002 2. 684 138. 9 109. 5

1 RT means room temperature. GGelled out in 210 F. viscos ity tube after 30-60 minutes.

In the Tables 7-13 above a number of different additives are defined by trade names. Paratone 430 and Paratone 460 are both vinyl acetate/fumarate copoly mers, the latter being of higher molecular weight than the former and possibly being made of different fumarates. The detergent additive Amoco 121 is a basic barium detergent lubricating oil additive which is a P S -hydro- 20 of mineral oil, a minor amount sufficient to improve the viscosity index of said mineral oil of oil-soluble isobutylene/dialkyl fumarate polymer, said dialkyl fumarate hav ing an average number of not more than carbon atoms in said alkyl groups but at least a sufiicient average numher of carbon atoms to give an oil-soluble polymer and carbon reaction product containing an appreciable amount of barium. The experimental barium detergent is a different type of material than the Amoco 121 but does contain an appreciable amount of barium. The last of the barium-containing detergents is another commercial additive Santolube 333, and this commercial detergent ditTers chemically from both the experimental barium detergent and the Amoco 121." Upon examining the data of Tables 7-13 it will be noted that the Amoco 121 is in general more reactive with the V.I. improvers than the other two detergent additives. A further examination of the tables indicates that both Paratone 430 and 460 are very unstable in the presence of barium detergents whereas the V1. improvers of the invention are sufiiciently stable to be usable in lubricating oils in the presence of barium detergents. lncTable 8 it will be noted that the Paratone 460 was so unstable in the presence of Amoco 121 that the entire oil gelled in a number of instances. In other words it can be concluded that whereas the V.I. improver additives of the invention are usable in lubricating oils in the presence of barium detergents, the Paratone type V.I. improvers such as 430 and 460 are not sufliciently stable to be usable in lubricating oils in the presence of barium detergents.

Some of the additives of the invention are in addition to being V.I. improvers also pour point depressants. For example, Base Oil No. 2 has a pour point of F.,

0.05 weight percent of the additive of Example 19 reduces this pour point to -15 F. and 0.25 weight percent of this same additive of the invention reduces the pour point of Base Oil No. 2 to 20 F.

Although the invention has been described in terms of specified embodiments which are set forth in considerable detail, it should be understood that this is by way of illustration only and that the invention is not necessarily limited thereto, since alternative embodiments and operating techniques will become apparent to those skilled in the art in view of the disclosure. Accordingly, modifications are contemplated which can be made without departing from the spirit of the described invention.

What is claimed is: V

1. A mineral oil composition of improved viscosity index and hydrolysis stability comprising a major amount said polymer and isobutylene existing in a 1 to 1 molar ratio in said mineral oil composition, and a minor amount of a barium-containing detergent additive. 1

2. A composition of claim 1 wherein said fumarate is a mixture of lower and higher dialkyl fumarates.

3. A composition of claim 1 wherein at least some of the fumarate molecules have a lower and a higher alkyl group.

4. A composition of claim 1 wherein said polymer is an isobutylene/dialkyl fumarate/isopropenyl acetate polymer.

5. A composition of claim 1 wherein said polymer is an isobutylene/dialkyl fumarate/vinyloxyethanol polymer.

6. A composition of claim 1 wherein said polymer is an isobutylene/dialkyl fumarate/vinyl ethyl ether polymer.

7. A composition of claim 1 wherein said polymer is an isobutylene/dialkyl fumarate/ vinyl acetate polymer.

8. A mineral oil composition of improved viscosity index and hydrolysis stability comprising a major amount of mineral oil, a minor amount sutlicient to improve the viscosity index of said mineral oil of oil-soluble isobutylene/dialkyl fumarate polymer, said dialkyl fumarate having an average number of not more than 10 carbon atoms in said alkyl groups but at least a sufiicient average number of carbon atoms to give an oil-soluble polymer and said polymer and isobutylene existing in a 1 to 1 molar ratio in said mineral oil compositions, and a minor amount of a basic detergent additive.

References Cited by the Examiner UNITED STATES PATENTS 2,543,964 3/51 Giammaria 25256 2,570,788 10/51 Giammaria 26078.5 2,710,282 6/55 LinSk et a1 252-56 2,824,836 2/58 Smith et a1 252-56 X 2,936,300 5/60 Tutwiler et al 25256 X DANIEL E. WYMAN, Primary Examiner.

JULIUS GREENWALD, ALPHONSO D. SULLIVAN,

Examiners. 

1. A MINERAL OIL COMPOSITION OF IMPROVED VISCOSITY INDEX AND HYDROLYSIS STABILITY COMPRISING A MAJOR AMOUNT OF MINERAL OIL, A MINOR AMOUNT SUFFICIENT TO IMPROVE THE VISCOSITY INDEX OF SAID MINERAL OIL OF OIL-SOLUBLE ISOBUTYLENE/DIALKYL FUMARATE POLYMER, SAID DIALKYL FUMARATE HAVING AN AVERAGE NUMBER OF NOT MORE THAN 10 CARBON ATOMS IN SAID ALKYL GROUPS BUT AT LEAST A SUFFICIENT AVERAGE NUMBER OF CARBON ATOMS TO GIVE AN OIL-SOLUBLE POLYMER AND SAID POLYMER AND ISOBUTYLENE EXISTING IN A 1 TO 1 MOLAR RATIO IN SAID MINERAL OIL COMPOSITION, AND A MINOR AMOUNT OF A BARIUM-CONTAINING DETERGENT ADDITIVE. 